The present invention relates to a butting ring for a rotor shaft, particularly of an electric motor.
A rotor shaft journalled in bearings will generally have some axial clearance, and thereby be movable axially in the bearings. It has thus become usual to provide the rotor shaft with at least one butting ring to limit the axial movement of the rotor shaft, at least in one direction, by causing the rotor shaft, or a part associated therewith, to abut a stationary stop face of the butting ring. Such arrangements are frequently used, for example, where the rotor shaft is provided in a motor, for example, an electric motor.
However, in the same way as the motor bearings, the butting surface of the butting ring must be lubricated.
During manufacture, a lubricant is introduced at the corresponding location of the butting ring and this supply is generally sufficient for a certain motor running time, and frequently, even, for the entire motor life. The butting surface abuts against, for example, the front end of a bearing, (in general a journal bearing or against a sliding disc, which is generally made from steel), which is positioned axially upstream of said front end of the bearing.
It is an object of the present invention to ensure that there is a lubricant supply for the butting ring of a rotor shaft for a maximum period of time, and that there is little risk of the lubricant supply proving inadequate, being lost or reaching unfavourable points of the motor.